def get_instrument_values(self,inst_id=None,position=None,ts=None):
""" given an instrument id and either a position name or timestamp
return a list of (pvname,values) tuples for all PVs in that instrument.
returns list_of_pv_values
where list_of_pv_values is a list of (pvname,values)
Note that the values returned may be None, meaning 'unknown'
"""
if position is not None:
try:
pos_id,pos_name,ts,a = self.get_positions(inst_id=inst_id,name=position)[0]
except IndexError:
ts = None
if ts is None:
return ([], 0)
pvs = [i['pvname'] for i in self.inst_pvs.select(where="inst=%i" % inst_id)]
data = dict.fromkeys(pvs,None)
a = Archiver()
for pvname in pvs:
for d in a.get_data(pvname,ts-3600.0,ts)[0]:
if d[0] <= ts: data[pvname] = d[1]
a.db.close()
pvnames = data.keys()
pvnames.sort()
vals = [(p,data[p]) for p in pvnames]
return vals,ts
